This invention relates to a connector and, in particular, to an electrical connector suitable for use in, for example, high-speed differential transmission.
For example, an electrical connector of the type is disclosed in Japanese Patent (JP-B) No. 3564555. The electrical connector comprises a plurality of contact groups each of which includes a pair of signal contacts and a ground contact, and is surface-mounted to a substrate. Each of the contacts has a contacting portion to be contacted with a mating connector and a terminal portion to be connected to the substrate.
In the Japanese Patent (JP-B) No. 3564555, the contacting portions are arranged in two rows. Further, the signal contacts in every two adjacent contact groups are disposed in rows different from each other. In other words, the signal contacts in one contact group are disposed in one of the rows while the signal contacts in another contact group adjacent to the one contact group are disposed in the other row. As a result, the signal contacts in every two adjacent contact groups are relatively distant from each other. Accordingly, there is no risk of degradation of electrical performance due to crosstalk.
On the other hand, the terminal portions are arranged in a single row. In each contact group, the ground contact is disposed between the paired signal contacts. As a result, the signal contacts in every two adjacent contact groups are disposed adjacent to each other. Accordingly, there is a risk of degradation of electrical performance due to crosstalk between every two adjacent contact groups.